A variety of different types of clamping devices have been used in agricultural applications to connect an agricultural tool to a movable support. The tool bar clamp is a common type of clamp presently in use. A typical tool bar clamp is shown and described in a copending application U.S. Ser. No. 643,879, now U.S. Pat. No. 4,585,073, assigned to the assignee of the present invention. Tool bar clamps generally include a clamp body with a vertical slot of rectangular shape that is open at the top and bottom and is closed along the sides and ends. The clamp body engages a tool bar and a clamp bracket and bolts extend through the bracket and into the clamp body to fasten the clamp body to the tool bar. A locking bolt extends through one end of the clamp body into the slot against the end of a tool-supporting shank to urge the shank against the opposite end wall of the clamp body. A disadvantage of this clamping arrangement is an inability to hold heat treated shanks.
Conventional bolts having a head at one end and external threads at the opposite end have been passed through the free end portions of a pair of spaced clamping members with the head and a nut threaded thereon applying clamping forces to an element between the plates. One person has difficulty in loosening these bolts and adjusting the height of the shank and tool.
Eccentric bolts having an eccentric section adjacent the head and larger in diameter than the shaft section have been used to exert clamping forces in a direction transverse to the longitudinal axis of the bolt.
U.S. Pat. No. 1,671,664 discloses an eccentric bolt supported in a U-shaped bracket to releasably clamp a shank of circular cross section to a bracket. The eccentric bolt has axially spaced shaft sections disposed along a common longitudinal axis and an eccentric or off-center section larger in size than the adjacent shaft sections supported in the bracket. The eccentric section is moved against a wedge that engages a circular tube to clamp the tube to the bracket. The clamping forces applied to the shank in this arrangement are applied from one direction only.